Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Chinese Academy of Sciences, Wuhan, Hubei 430074, China.
BMC Evol Biol. 2013 Aug 13;13:169. doi: 10.1186/1471-2148-13-169.
Patterns of genetic diversity between and within natural plant populations and their driving forces are of great interest in evolutionary biology. However, few studies have been performed on the genetic structure and population divergence in wild emmer wheat using a large number of EST-related single nucleotide polymorphism (SNP) markers.
In the present study, twenty-five natural wild emmer wheat populations representing a wide range of ecological conditions in Israel and Turkey were used. Genetic diversity and genetic structure were investigated using over 1,000 SNP markers. A moderate level of genetic diversity was detected due to the biallelic property of SNP markers. Clustering based on Bayesian model showed that grouping pattern is related to the geographical distribution of the wild emmer wheat. However, genetic differentiation between populations was not necessarily dependent on the geographical distances. A total of 33 outlier loci under positive selection were identified using a FST-outlier method. Significant correlations between loci and ecogeographical factors were observed.
Natural selection appears to play a major role in generating adaptive structures in wild emmer wheat. SNP markers are appropriate for detecting selectively-channeled adaptive genetic diversity in natural populations of wild emmer wheat. This adaptive genetic diversity is significantly associated with ecological factors.
自然植物种群内和种群间遗传多样性的模式及其驱动力在进化生物学中非常重要。然而，使用大量与 EST 相关的单核苷酸多态性（SNP）标记研究野生二粒小麦的遗传结构和种群分化的研究较少。
本研究中，使用了代表以色列和土耳其广泛生态条件的 25 个天然野生二粒小麦种群。利用超过 1000 个 SNP 标记研究了遗传多样性和遗传结构。由于 SNP 标记的双等位基因特性，检测到了中等水平的遗传多样性。基于贝叶斯模型的聚类表明，分组模式与野生二粒小麦的地理分布有关。然而，种群间的遗传分化并不一定取决于地理距离。使用 FST-outlier 方法鉴定出 33 个受正选择影响的外显子标记。观察到位点与生态地理因素之间存在显著相关性。
自然选择似乎在野生二粒小麦中产生适应性结构方面发挥了主要作用。SNP 标记适合检测野生二粒小麦自然种群中受选择影响的适应性遗传多样性。这种适应性遗传多样性与生态因素显著相关。
